pivot joint vs rotatory joint

pivot joint and rotatory joint both are nouns.

Word	Noun	Adjective	Verb	Adverb
pivot joint	Yes	No	No	No
rotatory joint	Yes	No	No	No

As nouns, pivot joint and rotatory joint are synonyms defined as:

pivot joint and rotatory joint: a freely moving joint in which movement is limited to rotation

Other synonyms of pivot joint include articulatio trochoidea, rotary joint.

pivot joint (noun)	rotatory joint (noun)
a freely moving joint in which movement is limited to rotation	a freely moving joint in which movement is limited to rotation